Computer networks that facilitate data communication between computing devices via a network of communications channels can suffer from faults or other forms of connectivity degradation. Such degradation can have a significant impact upon network performance and user experience.
Fault detection in a Local Area Network (LAN) can be conducted using the Internet Control Message Protocol (ICMP). An ICMP Echo Request, also known as an ICMP Ping, is a request-response message that is directed to a given IP address. ICMP Pings provide additional functionality added on top of the fundamental networking commands within a LAN, and can be used to probe devices associated with given IP addresses for connectivity problems or other responsiveness problems (for example, if a device is not responsive, it may be down or experiencing internal difficulties in processing or responding to ICMP Ping requests, which may be indicative of difficulties in processing or responding to other requests).
A fault-tolerant host in a LAN can include a so-called “redundant connection” to the LAN that comprises two Ethernet adaptors for connection to the LAN; a main adaptor that is used as a default connection to the LAN and a second adaptor to which the host can “failover” should connectivity degradation occur in relation to the first adaptor. Following the failover, the host communicates in the LAN using the second adaptor. If the LAN supports one or more Virtual LANs (VLANs) and the host is configured to participate in several different VLANs by specifying an Institute of Electrical and Electronics Engineers (IEEE) 802.1Q VLAN tag on its Ethernet frames, the host can failover all of its traffic, including all of the traffic on each VLAN, to the second adaptor.
Although this provides some level of fault tolerance in a LAN supporting one or more VLANs, it would be desirable to provide improved fault-tolerant methods and apparatuses, in particular that provide additional control in relation handling faults in the LAN.